Millennium Thermal Solutions was nice enough to send over a sample of their latest version, the Glaciator II. Millennium has taken a whack at lightening the Glaciator and improving airflow by carving out the base:

This allows cooling air to flow down onto the CPU, which does some additional cooling of both the CPU and in-socket thermistor.

The base is well finished and smooth to the touch. It is shipped with a protective plastic cover – make sure you remove it before use!

The clip is one of the best I have used – very easy to engage the socket’s lugs, no screwdriver required.

The Glaciator has 21 fins:

The fins in the bottom piece are cut from a solid copper block, so there is no solder joint. The top half is a separate assembly soldered onto the bottom. The annular rings in the top are soldered to the top cover. Note that there is a fair amount of space between the fins – airflow through the sink is important to its effectiveness.

The fan is mounted in a well – it is possible to remove it (not easily – it is glued in) and replace it with a Delta 38 if you’re so inclined, but don’t expect radical performance gains – maybe 2-3 C at best¹. You have to remove the Delta 38 from its case and fit it into the Glaciator body. Then you’ll have another noisy heatsink.

THE TEST

I prepared the Glaciator II by boring a hole completely through the base so I could epoxy a thermocouple above the CPU. The thermocouple is attached to an Omega HH23 Digital Thermometer. Ambient temps were measured with a thermocouple placed about 1 inch from the fan’s intake. I used Prime 95 to stress the CPU on an Iwill KK266+ and Iwill BD133/u (MBM temps are on-die). Arctic Silver grease was used in all tests. CPU Case Temp is the temp at that point where the CPU contacts the heatsink, CPU Back Temps are measured by a thermocouple on the center back of the CPU.

Fan noise was moderate – I measured it at 62 dBA 8″ from the fan intake with a Radio Shack sound meter – about the same as a 26 cfm YS Tech.

The Glaciator II was also tested on the CPU Die Simulator which gives results that are unaffected by motherboard influences.

TEST RESULTS – CPU Simulator

Heatsink

Die Temp

Ambient Temp

Delta

C/W

Glaciator II @ 78 watts

46.1 C

20.0 C

26.1 C

0.34

TEST RESULTS – Motherboards

CPU/Motherboard

CPU Case Temp

Ambient Temp

Delta

C/W

MBM Temp

CPU Back Temp

T-Bird @ 1400/Iwill KK266+

41.5 C

24.1 C

17.4

0.24

34 C

42.7 C

XP 1600 @ 1400, ASUS A7V266E

39.7 C

22.3 C

17.4

0.26

NA

NA

Celeron 1.2 @ 1600/Iwill BD133u

31.2 C

21.8 C

9.4

0.22

41 C

NA

PIII @ 933/Iwill BD133u

30.3 C

23.0 C

7.3

0.29

33 C

NA

Delta = CPU temp – Ambient Temp C/W = Delta / CPU Watts

Interpreting C/W: For every watt the CPU radiates, the heatsink will cool the core by the (C/W x watts) plus ambient temp. For example, at an ambient temp of 25 C, a C/W of 0.25 with a CPU radiating 50 watts means that the CPU temp will be 50 x 0.25 = 12.5 C over ambient temp, or 37.5 C. The lower the C/W, the better.

I was particularly interested in the Celeron 1200 results; if you calculate C/Ws from the on-die temps, you get 0.40 for the PIII and 0.45 for the Celeron. It looks like the thermal interface between the cap and the heatsink cost about 2 C in performance².

Finally, I did a head-to-head test with an original Glaciator on the CPU Simulator with these results:

Heatsink

Die Temp

Ambient Temp

Delta

C/W

Glaciator II, 137.5 watts

69.5 C

21.9 C

47.6

0.35

Glaciator, 137.7 watts

73.3 C

22.3 C

51.0

0.37

Looks like Millenium did their homework – there is a noticeable improvement over the original design; depending on the motherboard and case airflow, you may see improvements in the low single-digits.

CONCLUSIONS

The Glaciator II looks like a nice upgrade to the original Glaciator – lighter and improved performance. For those seeking good performance at reasonable noise levels, the Glaciator II is worth a serious look.

¹The latest batch of performance heatsinks are all banging up against a performance barrier – you can only go so far with current technology. The difference among the top performers is not more than 3-4 C.

²If you calculate the Celeron’s on-die C/W at 0.40, the delta temp would be 17 vs 19.2 observed. If you add 2 C onto the PIII results, you get a C/W of 0.46, which is about bang-on to the Celeron’s observed on-die C/W of 0.45. Loose the cap and get an additional 2 C in cooling.